A void exists in the application of theory to discover what the muscular coordination strategy ought to be and why that strategy is essential for the body to achieve a given motor task. One relevant technique to use is based on optimal control theory since it is a highly developed framework for analysis of complex dynamical systems. This technique, should it be applied to motor control, could be used to suggest optimal strategies for rehabilitative training and physical therapy, for reconstructive orthopaedic surgery, and for the training of athletes. Optimal control theory requires a mathematical formulation of the task to be optimized. The major problem associated with the few previous attempts employing such theory is that the performance criterion cannot be specified with certainty. Pur choice to study maximal height jumping circumvents this problem. Our approach is to use a symbiosis of state-of-the-art engineering theory and experimental techniques to study jumping by cats and humans. Analysis and computational methods developed and used by us to comprehend jumping by humans using only ankle rotation for propulsion will be extended to find the features that jumpers should exhibit as they achieve maximum height under less constrained conditions. The quantitative features of muscular coordination needed to maximize performance depend on accurate specification of some of the basic properties of myoactuators. Experiments will be performed to measure isometric torques developed at the hip, knee and ankle joints for a variety of leg positions during maximum voluntary contractions in humans and during maximum electrically-induced contractions in cats. The two-part control strategy and the performance features that jumpers should exhibit during propulsion will be compared with those occurring in cat and human jumps for which we already have force-plate, kinematic and electromyographic data. Specifically, we will determine if the unique muscular coordination pattern defining the second part of the optimal jump is actually observed. We will use theory to study how performance degrades with changes in control strategy and how it sould be enhanced with changes in body parameters and muscle properties.